Texas Instruments TMS320C67X/C67X+ DSP - Manual (Page 314)

SUBAB Subtract Using Byte Addressing Mode
3-254 Instruction Set SPRU733
Example SUBAB .D1 A5,A0,A5
Before instruction 1 cycle after instruction
A0 0000 0004h A0 0000 0004h
A5 0000 4000h A5 0000 400Ch
AMR 0003 0004h AMR 0003 0004h
BK0 = 3 → size = 16
A5 in circular addressing mode using BK0